Citrus fruits are generally harvested by hand picking and the conventional harvesting method includes the use of pick sacks, pallet tubs, and expensive in-grove vehicles with booms. More specifically, during a typical harvesting operation, a citrus fruit picker picks the fruit from a tree and places it in a pick sack which is carried over his/her shoulder. When the pick sack is full, the fruit picker carries it to a pallet tub and lifts the sack about thirty inches to empty the fruit into the pallet tub, and then returns to the same or a next tree with an empty sack to repeat the cycle. The height of the top edge of the conventional pallet tub is approximately thirty (30) inches from the ground.
A full pallet tub will commonly have a ten box capacity and will weigh about nine hundred pounds. A full tub will usually be emptied shortly after it is filled by an expensive in-grove vehicle with a boom, such as a field truck or "loader" (sometimes also called a goat) which moves along with the pickers during the harvesting process. A loader is a modified truck equipped with a rotatably mounted hydraulic boom specifically designed to lift and empty a fruit filled pallet tub into the loader's bed or hopper. The loader's bed is designed so that it may empty the fruit into a trailer which then hauls the fruit to a processing plant.
In a conventional harvesting operation, a large number of pallet tubs are strategically placed throughout the grove so that they will be substantially filled during a harvesting operation. Thus, the distance between the respective pallet tubs will be determined by the amount of citrus fruit on the trees between the pallet tubs. For example, in established citrus groves with "high density trees", the tubs will be arranged relatively close to one another. More particularly, a "high density" orange grove, or one having trees which are eight to ten years old, will yield about 1,100 oranges per tree. An average picker harvesting high density trees will fill his/her pick sack with about 45 pounds of fruit and empty the sack about 200 times a day.
In the above-identified applications, a fruit harvesting apparatus is disclosed which is particularly adapted for harvesting young citrus groves with "low density" trees. (For example, a low density orange grove will contain young trees which are two to four years old and which average about eight to twelve oranges a tree per year.) The apparatus includes a vehicle having a front end and a back end, and means for moving the vehicle along the ground. A tray is mounted to the vehicle (preferably the front end of the vehicle) for receiving the picked fruit and a pivotable hopper is mounted to the back end of the vehicle for temporarily storing the picked fruit. A transfer system is provided for transferring picked fruit from the tray to the hopper. The transfer system connects with the tray opening in such a manner that a smooth transition surface is formed between the tray and the transfer system. Initial experimental field tests indicate that such an apparatus results in a substantial increase in production when compared to that realized with pallet tubs and expensive loaders.
One design feature addressed in the previous applications concerned the height of the tray from the ground. More particularly, it is important that the height of the tray be such that lifting and emptying a potentially heavy container, such as a pick bag, does not unduly task the fruit picker. By providing a tray which has a top edge about twenty-four (24) inches from the ground, the tray is about six inches lower than a conventional pallet tub, requiring less effort to empty a pick sack into the tray as was previously required to empty a pick sack into a pallet tub. In such an arrangement, the side walls of the tray are approximately twelve (12) inches tall and thus the bottom wall of the tray is approximately twelve (12) inches from the ground.
The apparatuses disclosed in the above-identified applications were directed towards low-density harvesting operations. In contrast, the present application is directed towards improvements which, although useable in low-density harvesting operations, are particularly beneficial in high-density harvesting operations. One such improvement is positioning the tray so that its top edge is as close as possible to the ground. This positioning of the tray is extremely desirable because it reduces the height that a picker is required to lift his/her pick sack to empty it. As was indicated above, the top edge of a conventional pallet tub is thirty inches from the ground. As was also indicated above, an average picker harvesting high-density trees fills his/her pick sack with about 45 pounds of fruit and empties his or her pick sack about 200 times a day. Thus, eliminating the conventional pallet, and instead using a tray which has a top edge positioned, at about, for instance, five inches from the ground, saves an average picker the effort required to lift a 45 pound sack an extra twenty-two to twenty-four inches every time he/she empties the sack. In a single day, the average savings when using the tray would be approximately 370 feet.
By lowering the height of the top edge of the tray, the bottom wall of the tray is also lowered, preferably to a point essentially contacting, or resting, on the ground. In less then perfectly flat terrains (which most harvesting orchards are) such a positioning of the bottom wall would not provide sufficient ground clearance when moving the vehicle. Accordingly, the tray of the present invention is preferably selectively elevatable so that the bottom wall of the tray will have sufficient ground clearance when moving the vehicle. In this manner, the tray may be elevated prior to moving the vehicle and then lowered to receive fruit from the pickers. This feature is believed to be particularly advantageous in high-density harvesting operations because the machine remains in one position for long periods of time. Nonetheless, in some low-density situations, the reduction in labor due to the decreased height of the top edge of the tray may justify continuous elevation changes in the tray.
Thus, the selectively elevatable tray of the present invention solves the "ground clearance" problem while at the same time allowing the tray to be positioned at the desired "low" height. However, the lower positioning of the tray appeared to sometimes complicate other design features of the apparatus. Specifically, in the above-identified applications, the disclosed tray included an opening in one of its side walls which allowed a smooth transition surface between the tray and the transfer system. This smooth transition surface appeared to be sacrificed when the tray was lowered to the desired height because the angle between the tray and the transfer system decreased (or becomes more acute) which in turn increased the chance for clogging. The present invention is believed to solve this problem by positioning or extending the transfer system over the back wall in such a manner that a smooth transition surface is formed between a tray outlet and the transfer system, regardless of the height of the tray.
Additionally or alternatively, the tray of the present invention is selectively tiltable, thereby further guaranteeing a smooth transition between the tray outlet and the transfer system. This feature also allows the adjustment of the slope of the bottom wall when the terrain of the grove requires. Also, the tiltability of the tray, allows the fruit harvesting apparatus to negotiate culverts and other analogous obstacles. While the preferred fruit harvesting apparatus includes both an elevating assembly and a tilting assembly, the present invention contemplates the use of either of these assemblies independently in an apparatus.
These and other features of the invention are fully described and particularly pointed out in the claims. The following descriptive annexed drawings set forth in detail certain illustrative embodiments. However these embodiments are indicative of but a few of the various ways in which the principles of the invention may be employed.